Conventionally, a heat exchanger tube inserting apparatus is used for inserting, in a process of manufacturing a heat exchanger, a heat exchanger tube successively into insertion holes formed in each of a number of fins which have laminated so that the heat exchanger tube passes through the number of fins. For example, a heat exchanger tube inserting apparatus disclosed in Japanese Unexamined Patent Publication No. HEI 9-108760 includes guide rods respectively supporting a pair of leading ends of a U-shaped heat exchanger tube, and a heat exchanger tube inserting means for inserting the heat exchanger tube into insertion holes of a fin by pushing the curved portion of the U-shaped heat exchanger tube.
Each of the guide rods has a streamlined head at its leading end and is long enough to be inserted into insertion holes of each fin so as to pass through the number of fins. The streamlined heads located at the respective leading ends of the guide rods support the pair of leading ends of a heat exchanger tube while respectively being inserted in the opening formed at each of the pair of leading ends of the heat exchanger tube. Further, the guide rods can move through insertion holes of fins. This allows the guide rods to guide a heat exchanger tube to inner insertion holes while supporting the heat exchanger tube in insertion holes of the number of fins.
The heat exchanger tube inserting means is disposed at a position opposite to the guide rods in a direction of lamination of the number of fins. The heat exchanger tube inserting means can insert a U-shaped heat exchanger tube successively into insertion holes formed in each of the number of fins by pushing the curved portion of the heat exchanger tube toward the guide rods.
In such apparatus, the guide rods are inserted into insertion holes of the number of fins, in advance. Subsequently, the pair of leading ends of a heat exchanger tube is supported on the streamlined heads located at the respective leading ends of the guide rods. In this state, the curved portion of the heat exchanger tube is pushed by the heat exchanger tube inserting means from the side opposite to the guide rods, whereby the heat exchanger tube is inserted into the insertion holes of each of the fins. At this time, the guide rods are retreated at the same speed as an advancing speed of the heat exchanger tube, thereby allowing the heat exchanger tube to be inserted into the insertion holes of each of the number of fins while being supported by the guide rods.
However, in the above-described heat exchanger tube inserting apparatus, the guide rods and the heat exchanger tube inserting means which are long are disposed respectively on the opposite sides of the assembly of the number of fins in the direction of lamination. This results in an overall large size of the apparatus. Specifically, the guide rods need to be long enough to pass through the number of fins. Further, the heat exchanger tube inserting means needs to be long (have a stroke length) enough to push a heat exchanger tube from the beginning to the end in the insertion process of the heat exchanger tube. Therefore, the total length of the heat exchanger tube inserting apparatus needs to include not only the thickness of lamination of the number of fins, but also the full length of a heat exchanger tube at each of both sides of the assembly of fins in the direction of lamination. This results in a large size of the heat exchanger tube inserting apparatus. Therefore, it is difficult to make the apparatus smaller.
Furthermore, in the above-described heat exchanger tube inserting apparatus, the length of the guide rods and the stroke length of the heat exchanger tube inserting means limit the length of a heat exchanger tube that can be inserted. Therefore, there is a problem that the apparatus is not applicable to heat exchanger tubes having different lengths. In particular, there is a problem that the apparatus cannot insert an extremely long heat exchanger tube having a length exceeding the sum of the length of the guide rods and the stroke length of the heat exchanger tube inserting means.